firewall is a way of preventing certain information from passing
to one side of the firewall to another.
For example in an office set up it can stop employees looking
at inappropriate sites and stop external criminals accessing company
In home networks, a firewall typically takes one of two forms:
- Software firewall - specialised software (such as Zone
Alarm or Norton Internet Security) running on an individual
- Network firewall - a dedicated hardware device designed
to protect the whole network - Buy
Both types of firewall allow the user to set access policies for
inbound connections to the computers they are protecting.
Most will also provide control what services (ports) the protected
computers are able to access on the Internet (outbound access).
Most firewall's intended for home use come with pre-configured
security policies from which the user chooses, and some allow
the user to customize these policies for their specific needs.